19
J. pH Buffers
The temperature coefficient of pH calibration buffers 1.68, 4.00, 4.01,
6.86, 7.00, 9.18, 10.01 and 12.46 pH are stored inside the meter.
The buffers used to calibrate the meter must exhibit the same
temperature characteristics as the stored values.
Temperature coefficient of the pH buffers
[
Note:
The actual reading of the meter can differ from the values
shown by ±0.01 pH ]
K. Preparing Conductivity Standard Solutions
Suitable conductivity standards are available commercially or the
user can prepare them using research grade reagents.
Here are some standard solutions the user can prepare to calibrate
the probe of the model 6377MB/6377BEU.
1. Standard solution of 1413 uS/cm at 25
℃
: Accurately weight
out 0.746 grams of research grade dried Potassium Chloride
(KCL). Dissolve in 1000 ml of distilled water.
2. Standard solution of 12.90 mS/cm at 25
℃
: Accurately weight
out 7.4365 grams of research grade dried Potassium Chloride
(KCL). Dissolve in 1000 ml of distilled water.
3. Standard solution of 111.9 mS/cm at 25
℃
: Accurately weight
out 74.264 grams of research grade dried Potassium Chloride
°C
1.68 4.00 6.86 9.18 4.01 7.00 10.01 12.46
0
1.67
4.01 6.98 9.46 4.01 7.11
10.32 13.42
5
1.67
4.00 6.95 9.39 4.01 7.08 10.25 13.21
10
1.67
4.00 6.92 9.33 4.00 7.06 10.18 13.01
15
1.67
4.00 6.90 9.28 4.00 7.03 10.12 12.80
20
1.68
4.00 6.88 9.23 4.00 7.01 10.06 12.64
25
1.68 4.00 6.86 9.18 4.01 7.00 10.01 12.46
30
1.68
4.01 6.85 9.14 4.01 6.98 9.97
12.30
35
1.69
4.02 6.84 9.10 4.02 6.98 9.93
12.13
40
1.69
4.03 6.84 9.07 4.03 6.97 9.89
11.99
45
1.70
4.04 6.83 9.04 4.04 6.97 9.86
11.84
50
1.71
4.06 6.83 9.02 4.06 6.97 9.83
11.71
55
1.72
4.07 6.83 8.99 4.08 6.97 9.80
11.57
60
1.72
4.09 6.84 8.97 4.10 6.98 9.78
11.45
